In the framework of the present invention, the take-off procedure refers to the part of the take-off that connects the end of the actual take-off phase, for example at 35 feet (about 10 meters), to the point which marks the beginning of the ascending phase (speed of 250 knots, about 130 meters/sec, clean configuration). Such take-off procedure is defined under the form of a vertical profile that should be followed by the aircraft. The take-off procedure depends inter alia on the following elements:                the characteristics of the take-off airport (runway, obstacles, weather conditions);        data (engine speed upon take-off and, upon the ascent, take-off aerodynamic configuration) being defined by an operator, particularly the pilot; and        data being imposed by the air control authorities (speed and altitude stresses).        
The main operations to be implemented during the take-off procedure are as follows:                change of the engine speed (from the take-off speed to the ascent speed);        acceleration (towards the speed imposed by the air control); and        change of the take-off aerodynamic configuration towards a clean configuration (slats and flaps being retracted).        
The take-off procedure is further characterised by a high number of stresses, namely in particular regulating stresses so as to provide the required safety conditions, stresses due to the air control and stresses imposed by the aircraft systems.
Presently, the above mentioned operations are generally implemented by the pilot following a procedure being determined during the flight preparation and which is declared to the air control authorities before the aircraft departure. The possible procedures are simple, but are not optimized. Such procedures come generally from definitions provided by the International Civil Aviation Organization (ICAO). The International Civil Aviation Organization proposes two different departure procedures, namely a procedure ICAOA and a procedure ICAOB.
With more precision:                the procedure ICAOA is recommended to reduce noise in the inhabited zones near the airports. In such a case, thrust is reduced before starting to accelerate and change the aerodynamic configuration of the aircraft; and        the procedure ICAOB is recommended to reduce noise in the zones located far from airports. In such a case, the acceleration (and thus the resulting slats and flaps being retracted) is carried out at the take-off speed and thrust is reduced when the clean configuration (with slats and flaps completely retracted) is reached.        
The procedures ICAOA and ICAOB have been generalized so as to minimize noise. The (more general) resulting procedures are called procedures NADP (Noise Abatement Departure Procedure). However, such procedures NADP are fixed and not optimized or able to be optimized with respect to different criteria or particular objectives, such as for example the ecological impact or the economic cost of a take-off.
It is known that the civil aviation presently seeks to improve the ecological impact of the airplanes. Such environmental awareness concerns all components of the air transport, namely the authorities (airport, air traffic and aircraft certification), the airframe manufacturers, the engine manufacturers and the airway companies.
It is known that the environmental impact in the airport surroundings can be defined by the noise being caught on the ground, by the air quality, in particular via NOx production, and by the contribution to weather change, mainly represented by CO2 production. More precisely:                as regards noise, the very particular specificities of each airport (altitude, obstacles, inhabited zones in the surroundings, climate, etc.) make that presently surcharges regarding the operational noise depend on each airport; and        as regards CO2 and NOx emissions, there is a strong will to impose airport surcharges, but the new regulations, in particular the addition of a CO2 production tax at the fuel cost, are still in an investigation phase.        
Moreover, the economic cost minimization both regards fuel consumption, flight durations and use of engines. In addition, it is obviously appropriate to minimize the economic cost while respecting flight safety as well as air traffic stresses.
Consequently, the presently used take-off procedures are not adapted for the multiplicity of operational objectives and mainly for their characters being sometimes contradictory.